Murray Ashley, Horvath Arpad, Nelson Kara L
Energy and Resources Group and Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, USA.
Environ Sci Technol. 2008 May 1;42(9):3163-9. doi: 10.1021/es702256w.
Sewage sludge management poses environmental, economic, and political challenges for wastewater treatment plants and municipalities around the globe. To facilitate more informed and sustainable decision making, this study used life-cycle inventory (LCI) to expand upon previous process-based LCIs of sewage sludge treatmenttechnologies. Additionally, the study evaluated an array of productive end-use options for treated sewage sludge, such as fertilizer and as an input into construction materials, to determine how the sustainability of traditional manufacturing processes changes with sludge as a replacement for other raw inputs. The inclusion of the life-cycle of necessary inputs (such as lime) used in sludge treatment significantly impacts the sustainability profiles of different treatment and end-use schemes. Overall, anaerobic digestion is generally the optimal treatment technology whereas incineration, particularly if coal-fired, is the most environmentally and economically costly. With respect to sludge end use, offsets are greatest for the use of sludge as fertilizer, but all of the productive uses of sludge can improve the sustainability of conventional manufacturing practices. The results are intended to help inform and guide decisions about sludge handling for existing wastewater treatment plants and those that are still in the planning phase in cities around the world. Although additional factors must be considered when selecting a sludge treatment and end-use scheme, this study highlights how a systems approach to planning can contribute significantly to improving overall environmental sustainability.
污水污泥管理给全球各地的污水处理厂和市政当局带来了环境、经济和政治挑战。为了促进更明智和可持续的决策，本研究使用生命周期清单（LCI）对先前基于工艺的污水污泥处理技术生命周期清单进行了扩展。此外，该研究评估了一系列经过处理的污水污泥的生产性最终用途选项，如用作肥料和作为建筑材料的一种成分，以确定传统制造工艺的可持续性如何随着污泥替代其他原始投入而发生变化。污泥处理中使用的必要投入（如石灰）的生命周期纳入，对不同处理和最终用途方案的可持续性概况有重大影响。总体而言，厌氧消化通常是最佳处理技术，而焚烧，尤其是燃煤焚烧，在环境和经济成本方面最高。关于污泥的最终用途，将污泥用作肥料的抵消作用最大，但污泥的所有生产性用途都可以提高传统制造做法的可持续性。研究结果旨在为全球各城市现有污水处理厂以及仍处于规划阶段的污水处理厂的污泥处理决策提供信息和指导。尽管在选择污泥处理和最终用途方案时必须考虑其他因素，但本研究强调了系统规划方法如何能够显著促进提高整体环境可持续性。
